The Falk Cardiovascular Research Center, founded by Norman Shumway, is the core translational research facility of the Stanford Cardiovascular Institute (CVI), Department of Cardiothoracic Surgery, and Division of Cardiovascular Medicine. The requested instrument is to replace the 20-year-old x-ray fluoroscopy system in the Falk Center with a state-of-the-art system that combines 3 high-end functions necessary for advancing translational cardiovascular research - biplane imaging, high- speed frame rates, and rapid rotational imaging to provide CT-like soft-tissue imaging and 3D angiography. The Falk location is ideal as it has an entire floor dedicated to animal research, with preparation/housing facilities, operating rooms, 2D/3D echo systems, a 3T MRI system, and additional cardiovascular imaging and research equipment (physiologic/electrical monitoring, intravascular ultrasound, flow/pressure wires, etc.). A wide range of NIH-funded CVI users will benefit from this system, with projects ranging from myocardial/valvular mechanics, myocardial regeneration therapy/imaging, coronary and ventricular physiology, and image-guided cardiovascular interventions. Among the system's features, the biplane fluoroscopy (typically from two orthogonal planes) allows improved spatial guidance for advanced catheter-based interventions (e.g., myocardial delivery, electrophysiological ablation) as well as 3D localization of myocardial markers. High-speed frame rates (60fps) from both planes are critical for tracking rapidly moving myocardial and valvular markers and are advantageous at higher heart rates, allowing a broader range of animal models and physiologic conditions. Finally, rotational CT-like imaging opens a wide-range of capabilities - myocardial imaging to improve localization of cell/gene delivery or electrophysiological ablation plus 3D angiography to provide atrial/pulmonary vein mapping for ablation and provide arterial anatomic mapping for interventions - with adjacent 3T MRI/3D echo to compare and/or complement. With the ongoing challenge of supporting large-animal research facilities, this system is critical as a core research instrument in the Falk Center, the only Stanford facility capable of multi-disciplinary large-animal research. There is strong institutional commitment as it fosters to the long-term mission of the CVI - translating promising biological and technical developments from across the University through large-animal studies toward advances in patient care. PUBLIC HEALTH RELEVANCE: This proposal is to support a new, high-end x-ray imaging system to enhance research in heart and blood vessel disease. It will allow for the development and testing of novel methods to detect and treat cardiovascular disease to make sure they are safe and effective for use in patients. This funding will help support the jobs of Stanford researchers as well as the American jobs of the instrument company. It will also replace an older x-ray system with a more environmentally friendly system.